Implementing the Required Import Component Functions

Inside Macintosh: QuickTime Components

Implementing the Required Import Component Functions

Listing 1 supplies a sample program that implements a movie data exchange component that imports a Scrapbook file containing QuickDraw PICT images. (For details on QuickDraw PICT images, see the chapter "Basic QuickDraw" in Inside Macintosh: Imaging .) The sample program also provides the dispatchers for the movie import component together with the required functions.

Listing 1 Implementing the required import functions



 
#define kMediaTimeScale 600



 

typedef struct {

    ComponentInstance       self

    TimeValue               frameDuration;

} ImportScrapbookGlobalsRecord, **ImportScrapbookGlobals;



 

/* entry point for all Component Manager requests */

pascal ComponentResult ImportScrapbookDispatcher

                                         (ComponentParameters *params,

                                             Handle storage)

{

    OSErr err = badComponentSelector;

    ComponentFunction componentProc = 0;



 

    switch (params->what) {

        case kComponentOpenSelect: 

            componentProc = ImportScrapbookOpen; break;



 

        case kComponentCloseSelect: 

            componentProc = ImportScrapbookClose; break;



 

        case kComponentCanDoSelect: 

            componentProc = ImportScrapbookCanDo; break;



 

        case kComponentVersionSelect: 

            componentProc = ImportScrapbookVersion; break;



 

        case kMovieImportFileSelect: 

            componentProc = ImportScrapbookFile; break;



 

        case kMovieImportSetSampleDurationSelect: 

            componentProc = ImportScrapbookSetSampleDuration; break;



 

    if (componentProc)

        err = CallComponentFunctionWithStorage (storage, params,

                                                             componentProc);



 

    return err;

}



 

pascal ComponentResult ImportScrapbookCanDo 

                                    (ImportScrapbookGlobals storage, 

                                        short ftnNumber)

{

    switch (ftnNumber) {

        case kComponentOpenSelect: 

        case kComponentCloseSelect: 

        case kComponentCanDoSelect: 

        case kComponentVersionSelect: 

        case kMovieImportFileSelect: 

        case kMovieImportSetSampleDurationSelect: 

            return true;

        default:

            return false;

    }

}



 

pascal ComponentResult ImportScrapbookVersion 

                                        (ImportScrapbookGlobals storage)

{

    return 0x00010001;

}



 

pascal ComponentResult ImportScrapbookOpen 

                                    (ImportScrapbookGlobals storage,

                                     ComponentInstance self)

{

    storage = (ImportScrapbookGlobals) NewHandleClear 

                            (sizeof (ImportScrapbookGlobalsRecord));

    if (!storage) return MemError();

    (**storage).self = self;

    SetComponentInstanceStorage (self, (Handle)storage);

    return noErr;

}



 

pascal ComponentResult ImportScrapbookClose

                                         (ImportScrapbookGlobals storage,

                                             ComponentInstance self)

{

    if (storage) DisposeHandle((Handle)storage);

    return noErr;

}